Due to the many outdoor uses of padlocks, protective covers have been proposed to minimize the exposure of the padlock, particularly the keyway and the internal components of the padlock, to moisture and other contaminants, in an effort to extend service life by minimizing corrosion or oxidation of metallic lock components and damage caused by contamination. Previously proposed covers have been provided with a top portion to be fitted over the top end of the lock body, with openings to accommodate the shackle, and a bottom portion to be fitted over the bottom end of the lock body. However, the presence of a slit between the shackle openings, or sealing surfaces that deflect downward towards the shackles, may allow moisture to accumulate on the top portion of the cover and eventually seep past the cover and into the shackle holes.
To open the lock, the bottom portion of the previously proposed covers may be removed to access the keyway, or the bottom portion may be provided with an opening to access the keyway without removing the bottom portion. The opening in some proposed covers has been limited to a slit in the flexible bottom portion, allowing the material at the slit to be pressed open when a key is pressed against the slit for insertion in the keyway, or allowing the slit to be opened by squeezing the ends of the cover, similar to the operation of a plastic coin purse. After the key is removed from the lock, the slit contracts to its original form. However, this type of slit in the bottom cover may still allow moisture or other contamination to enter the keyway through the slit, particularly if repeated unlocking of the lock has resulted in plastic deformation of the cover material, causing the slit to widen.